Diesel fuel and lubricating oil antifoams and methods of use

ABSTRACT

The present invention relates to diesel fuel and lubrication oil defoaming agents, and crude oil demulsifiers, as well as methods for using same. In particular, the defoaming agents and demulsifiers are comprised of copolymers which have structures constituting a backbone of polysiloxane onto which is grafted an organic group. These structures comprise a polymer of the formula MD x  D&#39; y  D&#34; z  M, where M is O 0 .5 Si(CH 3 ) 3 , D is a OSi(CH 3 ) 2 , D&#39; is OSi(CH 3 )R, D&#34; is OSi(CH 3 )R&#39;, R is a polyhydric C 6  -C 28  organic group, R&#39; is a phenol derivative or a long chain aliphatic group or polyethers, z is between 0 and 80, x+y+z is between 10-200, x/z is ≧1, and x/(y+z) is between about 1 and about 5, or formula M&#39;D a  M&#39; where M&#39; is O 0 .5 Si(CH 3 ) 2  R, a is between 4-10, and R and D are the same as defined above.

This Application claims the benefit of U.S. Provisional Application60/014,836, filed Apr. 4, 1996.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to defoaming agents for petroleum products (suchas diesel fuel and lubricating oils) and crude oil demulsifying agents,and methods for using them.

2. Description of Related Art

Diesel fuel is a mixture of a variety of hydrocarbons. Most of thehydrocarbons are aliphatic, but aromatics may be present at up to twentyto twenty-five weight percent of the fuel. The mixture can also includekerosine or gas oil. Diesel fuel is commonly used in motor vehicles, andhas a tendency to foam profusely when it is poured into the fuel tank ofa motor vehicle. It is therefore desirable to reduce such foaming, whichcan be accomplished by the addition of a defoamer.

Oil companies treat diesel fuel with organic additives, such asdetergents, cetane improvers, viscosity breakers and occasionallyperfumes (collectively referred to as "DAP"). Each oil company has itsown preferred DAP which it typically uses only for mixing with its ownfuel. All of these organic additives must be compatible with thedefoamer.

Diesel fuels delivered to filling stations also may contain some amountof dispersed or dissolved water which can adversely affect theperformance characteristics of previously known defoamers. The watercauses a decay in defoaming characteristics and in some extreme cases,may cause the defoamer to enhance foaming, rather than suppress it. Suchwet defoamers also can result in increased sludge deposition in the fueltank.

U.S. Pat. No. 4,690,688 issued to Adams et al. discloses a typical priorart polysiloxane for use as a defoamer, wherein the polysiloxane is acopolymer with polyether side chains that provide at least 25 weightpercent of the copolymer. However, these polysiloxane copolymers do notwork well in wet diesel fuel because the ethers, as a hydrophilicmaterial, will tend to stabilize the foaming of wet fuel. Additionally,to function properly these polysiloxanes must be present at levels indiesel fuel above those desirable in engine systems.

DE 4032006 describes a process for defoaming and/or degassing organicsystems, including diesel oil, by adding a foam suppressant containingan organo-polysiloxane with unsaturated sidechains. A disadvantage ofthis foam suppressant is that it contains high levels of silicon, whichcan be harmful to engines. In addition, it can be incompatible with DAPand does not age well.

Lubricating oils are often comprised of mixtures of a hydrocarbon base(for example, mineral oil) and components which enhance lubricationperformance (esters, for example). For instance, typical oils containhighly refined parafinic hydrocarbon stock, or synthetic polyolefins.During application and use (for instance, in lubricating gear boxes orturbines), such lubrication oil products have a tendency to foamabundantly. Such foaming, in combination with the propensity in movingmachinery parts for air to be trapped, can adversely affect thelubricity, which can be detrimental to fast moving parts of machinery.Consequently, abatement of foam and rapid deaeration of lubricating oilsis a serious technical requirement for use of lubricating oils.

Standard silicone oils can be used to prevent foaming of lubricatingoils, and are efficient defoamers at very low rates (about 10-20 ppm).However, their use usually results in an undesirably low deaerationrate. The more efficient the silicone oil defoamer is the morepronounced is the problem of deaeration. For instance, silicone oilstypically trap and retain air for about 10 minutes after the stream ofpassing air is switched off.

Organic defoamers (such as polyacrylate-based defoamers, which arepresently popular in the art) are effective lubrication oil defoamers atconcentrations from about 100-200 ppm. However, their efficiency asdefoamers is very low at concentrations between about 10-50 ppm. Whileorganic defoamers provide a satisfactory deaeration rates, the treatrates are undesirably high, and are even several times higher than thetreat rates for silicone oils.

In testing these current defoamers, a strong stream of air is passedthrough oil during predetermined time and measuring the density of suchfrothed oil with time. The density of froth formed is much lower thanthat of a virgin air-free oil. The faster dearation means that thedensity of oil will be higher after, for example, 10 minutes. Thus, foran oil having a density of 0.872 the initial froth density is 0.810 dueto air whipped; it regains its original value for untreated oil after 10minutes while the densities after 10 minutes are 0.832 and 0.844 for oiltreated with 10 ppm of silicone oil or 200 ppm of organic defoamer,respectively.

In general, in the petroleum industry, before oil is shipped from arefinery it must go through a process of demulsification, wherebyundesired water is separated from the crude oil and removed. Currently,demulsification is carried out using an organic demulsifier, such asTROS6002X produced by TROS Company, in amounts of about 100 ppm. Theorganic demulsifier is usually dissolved in an aromatic compound, andthen added to crude oil to effect demulsification. The amount ofdemulsifier depends on the type of crude oil and amount of water in thecrude oil.

SUMMARY OF THE INVENTION

Accordingly, objects of the present invention include the development ofdefoamers that address the afore-described problems in the art.

In one embodiment, the invention contemplates a class of organosiliconecopolymers which may be used to abate the foaming of petroleum products,such as diesel fuel and lubricating oils. These copolymers havestructures constituting a backbone of polysiloxane onto which is graftedan organic group. Consequently, in this patent the term copolymers isintended to encompass organomodified polysiloxanes. In particular, thedefoaming agents can comprise a polymer of the formula MD_(x) D'_(y)D"_(z) M, where M is O₀.5 Si(CH₃)₃, D is a OSi(CH₃)₂, D' is OSi(CH₃)R,where R is a polyhydric (i.e., contains at least 2 hydroxyl groups) C₆-C₂₈ organic group, which preferably has a molecular weight betweenabout 134 and about 644, and which is completely saturated, D" isOSi(CH₃)R', where R' is a phenol derivative or a long chain (C₁₀ -C₂₀)aliphatic group or polyethers, z is between 0 and 80, x+y+z is between10-200 (and preferably between 20-160), x/z≧1, and x/(y+z) is betweenabout 2.0 and about 10.0 (and preferably between about 3.0 to about6.0). The polymer should be present in sufficient amounts (i.e.,effective amounts) to reduce foaming of petroleum products, andpreferably present at about 1.0 to about 5.0 ppm, which results in Silevels of between about 0.22 to about 1.10 ppm.

In addition to the previous formula, the defoaming agents can comprise apolymer of the formula M'D_(a) M' where M' is O₀.5 Si(CH₃)₂ R, R and Dare the same as defined above, and a is between 4-10 (and preferablybetween 5-8). The polymer should be present in sufficient amounts toreduce foaming of petroleum products, and preferably present at about 4ppm. The defoaming agents can be comprised of polymers of either formulaMD_(x) D'_(y) D"_(z) M or formula M'D_(a) M' alone, or can comprisemixtures of both.

In a related embodiment, the invention relates to methods of reducingfoaming of petroleum products. The methods comprise adding to apetroleum product (such as diesel fuel and lubricating oil) acomposition comprising a polymer of the formula MD_(x) D'_(y) D"_(z) M(as described above) and/or formula M'D_(a) M' (as described above), inamounts effective to reduce foaming of the petroleum product (asdescribed above).

It is a further object of the present invention to provide lubricatingoil defoamers which demonstrate an acceptably high rate of deaeration.Thus, in another embodiment, the invention contemplates a class oforganosilicone copolymers which may be used to defoam lubricating oil.These copolymers can comprise a polymer of the formula MD_(x) D'_(y)D"_(z) M (as described above) and/or formula M'D_(a) M' (as describedabove), and should be present in sufficient amounts to effect defoamingof lubricating oils, preferably below 100 ppm, and more preferablybetween 20 and 50 ppm. The defoaming agents can be comprised of polymersof either formula MD_(x) D'_(y) D"_(z) M or formula M'D_(a) M' alone, orcan comprise mixtures of both.

In a related embodiment, the invention relates to methods of defoaminglubricating oil. The methods comprise adding to lubricating oil acomposition comprising a polymer of the formula MD_(x) D'_(y) D"_(z) M(as described above) or formula M'D_(a) M' (as described above), inamounts sufficient to effect defoaming of lubricating oil, preferablybetween 20 and 50 ppm.

It is a further object of the present invention to develop crude oildemulsifiers that address the afore-described problems in the art. Thus,in another embodiment, the invention contemplates a class oforganosilicone copolymers which may be used to demulsify crude oil.These copolymers can comprise a polymer of the formula MD_(x) D'_(y)D"_(z) M (as described above) and/or formula M'D_(a) M' (as describedabove), and should be present in sufficient amounts to effectdemulsification of crude oil preferably present at about 5 ppm. Thedemulsifying agents can be comprised of polymers of either formulaMD_(x) D'_(y) D"_(z) M or formula M'D_(a) M' alone, or can comprisemixtures of both.

In a related embodiment, the invention relates to methods ofdemulsifying crude oil. The methods comprise adding to crude oil acomposition comprising a polymer of the formula MD_(x) D'_(y) D"_(z) M(as described above) or formula M'D_(a) M' (as described above), inamounts sufficient to effect demulsification of crude oil, preferablybetween about 5 ppm.

The copolymers of this invention are themselves novel compounds,irrespective of their suitability as a defoamer of diesel fuel orlubricating oil. This is especially the case where the R group is analkoxylated allyl sorbitol derivative, an alkoxylated pentaerythiolderivative, and an alkoxylated or non-alkoxylated trimethylpropanederivative.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The copolymer compositions of the invention include low molecular weightorganic moieties of R described above. The hydroxy groups of theseorganic sidechains effect a high polarity. In some specific cases thepolarity of a molecule containing two or more hydroxyls can be adjusted(i.e., reduced) via transformation of a polyhydroxy group into acorresponding acetal or ketal.

The presently described copolymer allows for a low treat rate in dieselfuel and this corresponds to a very low silicon level in fuel (e.g., aslow as 0.5 ppm). Thus, one can expect the complete elimination or asubstantial reduction of the problems presented by defoamers currentlyin use. Moreover, the copolymers of the present invention demonstratehigh stability in diesel fuel wherein water is dispersed or dissolved.

The advantages of the present invention are made possible by thecografting of the low molecular weight, compact, high polarity organicgroups onto a silicone backbone. The substitution of the organic groupssurprisingly improves the defoaming ability of the copolymer because itenhances defoaming efficiency and helps to maintain the performancecharacteristics of the copolymers in diesel fuel wherein water isdispersed or dissolved, and because it allows the complete eliminationof foam at low silicon concentration.

In addition, the invention provides an entirely new structure forlubricating oil defoamer effective at concentrations 100 ppm or less,and preferably 50 ppm or less.

In addition, the invention provides an entirely new structure for acrude oil demulsifier, which is advantageous over previous knowndemulsifiers in that it is effective at very low amounts, such as 10ppm, whereas the previous known demulsifiers are only effective whenpresent in amounts of about 100 ppm.

Structure of the Copolymer

For the defoaming agents the class of organosilicone copolymers of thepresent invention is characterized by a combination of high molarfraction of D units and the presence of low molecular weight, compact,organic groups of high polarity. The advantageous properties of theinvention may be achieved by a careful selection of a siloxane backboneof the formula MD_(x) D'_(y) D"_(z) M and/or formula M'D_(a) M', asdescribed above. Although linear structures are specifically set forthherein, the invention also contemplates T and Q structures.

Varying the molecular weight of the polysiloxane generally does notalter the polymer properties, but rather the upper limit of x+y+z isdetermined by the technological capability to handle very viscoussilicone hydrides and the lower molecular weight limit is set by thefact that in smaller sized copolymers the distribution of modifiedgroups may cause some copolymers to have no modified groups, where afraction of the resulting material can be non-modified silicone oilwhich is either inert or may enhance foaming. The present inventionprefers the sum of x+y+z to be between about 10 to about 200, butsomeone skilled in this art would appreciate that improvements inproduction ability would allow for use copolymers outside of this range.

The physical properties of polysiloxane copolymer compositions of theinvention are determined by variables such as the size of siloxanechain, the degree of substitution with organic groups different thanmethyl and the nature (polarity) of organic moiety replacing an originalmethyl group in polysiloxane.

The organic groups (R) contemplated by the invention are mainlyaliphatic, low molecular weight diols. The organic group preferably hasa molecular weight between about 134 and about 644, and preferablybetween about 134 and about 400. In addition, the organic group iscompletely saturated. Before grafting, the organic group R bears anunsaturated terminus such as an allyl, methallyl or a vinyl. Forexample, the terminus can be an allyl, a methallyl or a vinyl. Theunsaturated terminus becomes saturated when the organic group ishydrosilated onto the siloxane backbone. Thus, the resulting siloxanecopolymer has no unsaturation.

The organic group grafted on polysiloxane can be described in terms ofsolubility parameter, which is a thermodynamic measure and is indicativeof cohesion forces. Solubility parameters can be calculated from knowntables. It is generally accepted that a higher value of solubilityparameter for a certain compound corresponds with a higher polarity ofthat compound. However, a high polarity does not necessarily mean asubstance will have high hydrophilicity, even though the converse istrue: highly hydrophilic substances have high polarity. Thus,alkylphenol derivatives (eugenol, for example) have a high polarity butare insoluble in water.

                  TABLE 1                                                         ______________________________________                                        trimethylolpropane monoallyl ether                                                                   25.3                                                   ethoxylated pentaerythritol allyl ether                                                              25.3                                                   propoxylated pentaerythritol allyl ether                                                             23.6                                                   tri-isopropanolamine allyl ether                                                                     20.3                                                   glycerol monoallyl ether                                                                             27.1                                                   ______________________________________                                    

Preferred solubility parameters range between 23 to 35.

For comparison, the adduct of seven moles of methyl capped ethyleneoxide on allyl alcohol has a solubility parameter of 18.2 while anethylene oxide unit has a solubility parameter of 19.2.

The organic group contemplates aliphatic polyhydroxy groups, theiralkoxylated derivatives or optionally the cyclic acetals obtained in thereaction of formaldehyde and polyhydroxy species (formals). Preferably,the precursor of the R group is trimethylolpropane monoallyl ether.However, the precursor of the R group can be ethoxylated pentaerythritolallyl ether, propoxylated pentaerythritol allyl ether,tri-isopropanolamine allyl ether, or allylpropanediol 1,3. Diols can betransformed into corresponding cyclic formals via reaction ofpolyhydroxy compounds with formaldehyde, and the resulting cyclicolefins can be grafted onto the siloxane backbone. Compounds suitablefor use as the R group are commercially available from, for instance,Perstorp AB of Sweden.

As someone skilled in the art would appreciate, the R group should bechosen so that the resulting organosilicone copolymer is insoluble inboth diesel and water. Thus, the selection of the R group must bebalanced against the size of the siloxane backbone to achieve thedesired hydrophobic/hydrophilic balance.

For example, by varying the total size of the organosilicones, i.e.,x+y+z, the ratio of siloxane groups, i.e., x/(y+z), and the nature ofthe grafted groups, R, one may design a copolymer for particular gradesof fuels, particular engine systems and particular conditions of use.The ratio x/(y+z) defines the hydrophilic properties of the copolymermade of a given set of grafted groups and may be adjusted according tothe water content of the fuel with which the copolymer is to be used.

For example, a small R group contemplated by this invention is anallylpropanediol 1,3, whereas a large R group is an ethoxylated allylsorbitol. Many of the organosilicones of this invention are themselvesnovel compounds, especially where the R group is ethoxylated allylsorbitol.

An especially preferred R group is trimethylolpropane monoallyl ether(TMPMAE). Other R groups useful in the invention include ethoxylatedpentaerythritol allyl ether, propoxylated pentaerythritol allyl ether,tri-isopropanolamine allyl ether, and allylpropanediol 1,3. TMPMAE andits derivatives provide more surface activity than polyether derivativesfor the same siloxane backbone, in spite of the fact that TMPMAE has ahigher polarity. This is believed to be due to the compact molecularstructure of TMPMAE.

For example, in a preferred composition for both a defoaming agent and acrude oil demulsifier x is 100, y is 24, z is 0, and R is TMPMAE.Similarly, in another preferred composition R is TMPMAE and a is about7.0. The unique structure of these preferred compositions isparticularly advantageous in that the adsorption of the composition isenhanced on different types of surfaces. In addition, some mineralsurfaces, such as bentonite, and other surfaces, such as fabric, paperand concrete, may be rendered hydrophobic through the adsorption ofthese compositions. The adsorption of this preferred composition on aglass plate resulted in a substantial reduction of surface energy ofglass. In fact, it is estimated that surface tension of the glass wasreduced from about 72 dynes/cm to about 30 dynes/cm. Such a high surfaceactivity of compositions of this invention may explain their efficiencyin defoaming and demulsification. However, the extremely lowconcentrations of organosilicones of the invention does not easilypermit an investigation of the details of the mechanism of action. Theobservations related to the adsorption on solid surfaces may beconsidered as being parallel to phenomena which occur in a fuel or crudeoil and which are related to discrete intermolecular interactions oninterfaces.

Manufacture of the Copolymers

Methods for making the defoamer agents and demulsifier agents are knownin the art. For instance, U.S. Pat. No. 3,794,693 teaches how to makecopolymer compositions.

During manufacture, it is often advantageous to add a solvent to ensurethat the reactants are well mixed throughout the reaction. Solvents usedfor these purposes include DPG (dipropylene glycol), toluene and anyother solvent of which has suitable solubility characteristics, such as2-ethyl hexanol, isopropanol, various aromatic solvents such as SOLWESSO150, aliphatic ester alcohols such as TEXANOL(2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), isophorone, mixturesof same, and the like. With the copolymers of the invention, it is notnecessary to remove the solvent in order that the copolymers beeffective as defoamers. However, for the sake of safe transportation,volatile solvents such as toluene and isopropanol can optionally beremoved. Non-volatile solvents or those of a high flash point (e.g., DPGand ethylhexanol) do not pose the same safety problems, and there is noneed to remove them.

Some of the compositions of the invention (such as the preferredcomposition) are hydrophobic and will precipitate as a white gel whenintroduced into water.

Use of the Copolymers

For defoamers, the modified polysiloxane is typically blended with DAP(which is commercially available), and added to the petroleum product ata refinery. For demulsifiers, the polysiloxane copolymer is dissolved inan aromatic compound, and then added to the crude oil.

The polysiloxane copolymers of the invention should be added at about 5ppm to the diesel fuel. Preferably, a minimum amount of polysiloxanecopolymer is used and the preferred range of addition is at 2 ppm to 4ppm. The polysiloxanes of the invention should be added at about 10 ppmto about 50 ppm to the crude oil to provide adequate separation of thecrude oil and water content.

Characteristics of the Copolymer

The solubility pattern, molecular weight distribution and surfacetension reduction are physical properties useful to assess thecompositions of the invention.

Table 2 reveals the solubility pattern of one of organosilicones of theinvention made from MD100D*24M silicone hydride (D*=HSiOCH₃) and TMPMAEas a sole substituent.

                  TABLE 2                                                         ______________________________________                                        Solubility pattern of organosilicone made from                                MD100D*24M and TMPMAE                                                                     Concentration                                                                 of                                                                            MD100D'24M:                                                       Solvent     1%          5%      10%  20%  50%                                 ______________________________________                                        Diesel fuel No          No      No   No   No                                  2-Ethylhexanol                                                                            Yes         Yes     Yes  Yes  Yes                                 Xylene      No          No      No   No   Yes                                 SOLVESSO 100                                                                              No          No      No   No   Yes                                 SOLVESSO 150                                                                              No          No      No   No   Yes                                 Propylene   No          No      No   No   No                                  carbonate                                                                     VAMMAR D 10N                                                                              No          No      No   No   No                                  ______________________________________                                         Yes = soluble in solvent at ambient conditions                                No = insoluble in solvent at ambient conditions                          

The following illustrative and comparative examples describe the instantinvention in more detail. However, they are not intended to limit thescope of the specification and the claims.

EXAMPLES Organosilicone Examples Example 1

The equilibrate MD100D*24M (D*=HSiOCH₃), containing 2.5*10 (-3) mole ofactive hydrogen per gram was blended with TMPMAE and dipropyleneglycolwhich constituted 50% of the total charge. A 30% molar excess of allylbond was employed. Reaction was catalysed with 15 ppm of platinum addedas a solution of chloroplatinic acid. An exotherm of 15 deg. wasproduced and reaction came to completion within 45 minutes.

The product was applied as a diesel fuel defoamer at the concentrationequivalent to 1.1 ppm of silicon. The antifoam properties were recorded.In practical terms there was no foam formation.

Example 2

An equilibrate MD44D*11M of an active hydrogen content 2.5 mmoles pergram was blended with TMPMAE and dipropylene glycol and reaction wastriggered with 15 ppm of platinum at 70 deg. C. An exotherm about 15 degwas developed within several minutes and reaction was completed withinless than 45 minutes.

The product applied in diesel fuel at a concentration of 1.1 ppm ofsilicon exhibited excellent performance characteristics as the initialfoam volume was reduced to about 20% and the defoam time was about 10%of the blank (standard).

Example 3

An equilibrate MD100D*24M of an active hydrogen content 2.5 mmoles pergram was blended with TMPMAE and polyether composed of seven moles ofethylene oxide and terminated with methyl group (60/40 molar) and DPG asa reaction solvent. The reaction was triggered with 15 ppm of platinumat 70 deg. C. An exotherm about 15 deg was developed within severalminutes and reaction was completed within less than 45 minutes.

The product of reaction was applied as a defoamer in one of dieselsavailable on the French market. The product exhibited defoamingcharacteristics similar to that of Example 1. Both products applied atthe concentration 0.50 ppm of Si eliminated virtually all foaming as thevolume of foam was below 5% and the defoam time was between 1 and 4seconds.

Example 4

An equilibrate MD100D*24M of an active hydrogen content 2.5 mmoles pergram was blended with TMPMAE and polyether composed of seven moles ofethylene oxide and terminated with methyl group (50/50 molar) and2-ethylhexanol as a reaction solvent. The reaction was triggered with 15ppm of platinum at 70 deg. C. An exotherm about 15 deg was developedwithin several minutes and reaction was completed within less than 45minutes.

The product of reaction was applied as a defoamer in one of dieselsavailable on the French market. The product exhibited defoamingcharacteristics similar to that of Example 1. Both products applied atthe concentration 0.50 ppm of Si eliminated virtually all foaming as thevolume of foam was below 5% and the defoam time was between 1 and 4seconds.

Comparative Example (DE 4032006)

The equilibrate as described in example 2 was diluted with dioxane andan adequate amount of 1,4 butyn-2 diol was added. Reaction was catalysedwith a catalyst as described in the German patent (DE 4032006-A). Aboutforty hours and an extra catalyst and butyndiol were needed to completethe reaction.

The same performance as for Example 1 was achieved at about a fortypercent higher silicon concentration in diesel.

In all preparations a 30% molar excess of unsaturated bond was employed.

Diesel Antifoam Performances

The performance of diesel defoamer is assessed in terms of either thefoam volume obtained by injecting 100 cc of fuel to the graduatedcylinder or by time needed to achieve clean fuel surface in thecylinder. The time of defoaming is often expressed as a percent of timeneeded for a blank, untreated sample of fuel. In this case, lower valuesindicate faster foam collapse and more efficient defoamer.

The amount of silicon introduced into fuel should be as low as possibleand usually the efficiency of a defoamer increases with the increasedamount of silicon in fuel. Diesel fuels are very often treated with DAPadditives which are introduced into fuel to improve the performance ofthe engine. It is therefore important that the defoamer applied shouldmaintain its performance characteristics in the presence of DAP.

Table 3 records data related to several examples of the composition ofthe invention made with aliphatic diols as a sole grafted groupsincluding TMPMAE, allylglycerol, cyclic derivatives of diols and acomparative example with 2-butyn-1, 4 diol. An example with polyether asthe grafted group is also included. All organosilicones are diluted withthe reaction solvent and were prepared according to procedures describedin Examples 1 to 3 above and were applied at 10 ppm treat rate,irrespective of the silicon content in the molecule.

                                      TABLE 3                                     __________________________________________________________________________    Performance of diesel defoamers of different structures, all tested at 10     ppm                                                                           (products are diluted with the reaction solvent)                              siloxane backbone                                                                       olefin grafted                                                                          Reference                                                                             rel. collapse time (%)                            __________________________________________________________________________    NA        NA        blank   100                                               MD100D*24M                                                                              polyether/Eugenol                                                                       SAG TP-325,                                                                           24                                                                    commercial                                                MD100D*24M                                                                              TMPMAE    A       2                                                 MD100D*24M                                                                              TMPMAE/polyether                                                                        B       4                                                           (60/40 mol)                                                         MD102D*18M                                                                              TMPMAE    C       1                                                 MD44D*11M formal of D       94                                                          allylglycerol                                                       MD44D*11M formal of TMPMAE                                                                        E       88                                                MD44D*11M polyether, of seven                                                                     F       46                                                          moles of ethylene                                                             oxide on allyl                                                                alcohol                                                             MD44D*11M 2-butyn-1,4 diol                                                                        G       2                                                 MD44D*11M allylglycerol                                                                           H       2                                                 MD44D*11M TMPMAE    I       6                                                 MD48D*12M TMPMAE    J       16                                                MD42D*7M  TMPMAE    K       13                                                __________________________________________________________________________

The fuel used was obtained from SHELL and is a heavily foaming dieselproducing about 217 cc of foam from 100 cc of liquid with the defoamtime about sixty seconds. A dramatic loss of performance was recordedfor polyether and cyclic formals substituted siloxanes. The use of acyclic formal instead of diol reduced substantially the overall polarityof siloxane, for the same molar fraction of D units. The use of anuncapped polyether from seven moles of ethylene oxide reduced the molarfraction of D units from about eighty to fifty percent. The use ofcapped polyether instead of the uncapped one as quoted in Table 3results in the same mediocre performance.

The adjustment of the treat rate to the same silicon content modifiedthe order of efficiency of the defoamer. SAG TP-325 (that is, thestate-of-the-art commercial diesel fuel defoamer; (made by WITCOOrganoSilicone) was used as a reference at 10 ppm treat rate, which thiscorresponds to 0.90 ppm of silicon introduced into fuel. The same dieselfrom SHELL was used and findings for different defoamers, all at 0.90ppm of silicon, are collected in Table 4.

                  TABLE 4                                                         ______________________________________                                        Performance of diesel defoamers at 0.90 ppm of silicon in fuel                                    relative collapse                                         Reference                                                                             foam volume (cc)                                                                          time %      collapse time (sec)                           ______________________________________                                        blank   217                     66                                            TP-325  150         24          16                                            A       113         15          10                                            G       123         20          13                                            H       105         3           2                                             I       110         8           5                                             ______________________________________                                         (References A, G, H and I are the same as in Table 3.)                        It was apparent that the material G containing residual unsaturation was      outperformed by defoamers made with saturated olefins. Structures G, H an     I were all made with the same siloxane backbone.                         

It can also be demonstrated that the organosilicone containing theresidual unsaturation is more sensitive to ingredients of DAP and itsperformance will decline rapidly during aging.

Table 5 shows structures and performance, as a foam volume, of thediesel defoaming agents which are TMPMAE derivatives. Where the valuefor the volume of foam is equal or less than 105 cc (that is, from about100 cc to about 105 cc of fuel), this is indicative of no essentiallyfoaming, in practical terms. In contrast, foam volumes exceeding 150 ccindicates an unsatisfactory defoaming characteristics of theorganosilicone defoamer. Stable performance of a defoamer isparticularly important where formulated fuels are likely to be storedseveral weeks before their use. Example G and G type are organosiliconeswith residual unsaturation and correspond to the description of theabove Comparative Example. The loss of the performance is seen for Gtype derivatives. This degradation of performance is enhanced by thepresence of DAP.

The following foam volumes in Table 5 were found for various fuel whichwere either untreated or contained some DAP. The collapse time for thefoam volumes equal to or less than 105 cc is not addressed, since thereis essentially no foaming for these values.

                                      TABLE 5                                     __________________________________________________________________________    Structures and performance, as a foam volume,                                 of the diesel defoaming agents which are 100% substituted with TMPMAE              Diesel   ppm Si                                                                             volume (cc)                                                                         volume (cc)                                                                         volume (cc)                                    Reference                                                                          type                                                                              DAP ppm                                                                            in fuel                                                                            day 0 day 17                                                                              day 42                                         __________________________________________________________________________    TP-325                                                                             D1  200  0.45 130   130   +                                              A    D1  200  0.22 105   +     +                                              A    D1  200  0.55 105   +     +                                              B    D1  200  0.50 105   +     +                                              G type                                                                             D1  200  1.00 102   110   +                                              B    D2  none 0.50 105   130.sup.( *.sup.)                                                                   160.sup.( **.sup.)                             G type                                                                             D2  none 0.50 105   177.sup.( *.sup.)                                                                   183.sup.( **.sup.)                             I    D3  none 0.90 110   120   127                                            G    D3  none 0.90 120   140   173                                            G type                                                                             D3  none 0.90 105   208   205                                            I    D4  1000 0.90 105   110   140                                            G    D4  1000 0.90 167   190   190                                            G type                                                                             D4  1000 0.90 110   160   180                                            __________________________________________________________________________     += data not available                                                         .sup.(*.sup.) = 15 days                                                       .sup.(**.sup.) = 32 days                                                      (References A, B, G and I are the same as in Table 3.)Examples in diesel      D1 are to show the efficiency of new structures as related to silicon         content.                                                                 

Table 6 shows classification by molecular weight, and Table 7 showsclassification by performance (where lower values indicate moreefficient defoaming) for TMPMAE derivatives. Tables 6 and 7 describealso the total size of polysiloxane, the ratio of D/D', and the activityof product (degree of dilution).

                                      TABLE 6                                     __________________________________________________________________________    (TMPMAE)                                                                      Classification per mol. weight                                                Siloxane                                                                             Total D + D' (M')                                                                     D/D' (M')                                                                           Synthesis N°                                                                 % active                                                                           Performance 1)                                __________________________________________________________________________    M'D2M' 2     1       RH 368-248                                                                          80   95%                                           M'D3M' 3     1.5     MG 261                                                                              80   99%                                           M'D4M' 4     2       RH 368-202                                                                          75   72%                                           M'D5M' 5     2.5     MG 289                                                                              80   58%                                           M'D8M' 6     3       MG 292                                                                              80   94%                                           M'D7M' 7     3.5     MG 295                                                                              80   47%                                           M'D10M'                                                                              10    5       PH 368-288                                                                          50   89%                                           MD8D*2M                                                                              10    4       RH 17122-4                                                                          50   62%                                           M'D15M'                                                                              15    7.5     RH 368-289                                                                          50   96%                                           M'D20M'                                                                              20    10      RH 368-290                                                                          50   100%                                          MD'16D*4M                                                                            20    4       RH 17122-5                                                                          50   18%                                           MD24D*6M                                                                             30    4       RH 17122-6                                                                          50   12%                                           MD42D*7M                                                                             49    6       RH 368-214                                                                          50   13%                                           MD44D*11M                                                                            55    4       RH 368-260                                                                          50    6%                                           MD48D*12M                                                                            60    4       RH 368-203                                                                          50   16%                                           MD102D*18M                                                                           120   5.7     RH 368-212                                                                          50    1%                                           MD100D*24M                                                                           124   4.2     RH 368-170                                                                          50    2%                                           __________________________________________________________________________     Performance is gauged in relative collapse time.                         

                                      TABLE 7                                     __________________________________________________________________________    Classification per performance                                                Siloxane                                                                             Total D + D'                                                                        D/D' (M')                                                                           Synthesis N°                                                                 % active                                                                           Performance 1)                                  __________________________________________________________________________    M'D20M'                                                                              20    10    RH 368-290                                                                          50   100%                                            M'D3M' 3     1.5   MG 261                                                                              80   99%                                             M'D15M'                                                                              15    7.5   RH 368-289                                                                          50   96%                                             M'D2M' 2     1     RH 368-248                                                                          80   95%                                             M'D6M' 6     3     MG 292                                                                              80   94%                                             M'D10M'                                                                              10    6     RH 368-288                                                                          50   89%                                             M'D4M' 4     2     RH 368-202                                                                          75   72%                                             MD8D*2M                                                                              10    4     RH 17122-4                                                                          50   62%                                             M'D5M' 5     2.5   MG 289                                                                              80   58%                                             M'D7M' 7     3.5   MG 295                                                                              80   47%                                             MD16D*4M                                                                             20    4     RH 17122-5                                                                          50   16%                                             MD48D*12M                                                                            60    4     RH 368-203                                                                          50   16%                                             MD42D*7M                                                                             49    6     RH 368-214                                                                          50   13%                                             MD24D*6M                                                                             30    4     RH 17122-6                                                                          50   12%                                             MD44D*11M                                                                            55    4     RH 368-260                                                                          50    6%                                             MD100D*24M                                                                           124   4.2   RH 368-170                                                                          50    2%                                             MD102D*18M                                                                           120   5.7   RH 368-212                                                                          50    1%                                             __________________________________________________________________________     Notes:                                                                        1) Tested in Diesel Shell at 10 ppm and 20° C. (relative collapse      time)                                                                         Performance is gauged in relative collapse time.                         

Crude Oil Demulsification Performances

Several experiments were carried out with a crude from Trecate oilfield(North of Italy). The concentration of water was adjusted to 20% and thecrude oil was agitated to form an emulsion. The volume of separatedwater was recorded with time. The reference was an organic demulsifierfrom TROS Company.

Figures are collected in Table 8.

                  TABLE 8                                                         ______________________________________                                        Rate of Trecate crude oil separation                                                      5       10     15    30   60    120                               Sample      min     min    min   min  min   min                               ______________________________________                                         10 ppm TROS 6002X                                                                        0       0      0     5    5     5                                 100 ppm TROS 6002X                                                                        40      41     41    41   42    42                                 10 ppm RH 265                                                                            0       0      5     25   35    37                                MD100D'24M  25      33     35    38   38    40                                 10 ppm RH 273                                                                            0       5      25    30   35    37                                 10 ppm RH 275                                                                            0       0      0     0    5     10                                MD42D*7M    0       0      0     0    0     0                                 ______________________________________                                         RH 265 = MD44D*11M + polyether composed from seven moles of ethylene oxid     and terminated with an allyl group and a methyl group.                        MD100D'24M = Example 1 in organosilicone examples above.                      RH 273 = MD44D*11M + TMPMAE (as in Example 2 in organosilicone examples       above).                                                                       RH 275 = MD44D*11M + a cyclic formal made from TMPMAE and formaldehyde.       MD42D'7M = MD42D*7M + TMPMAE.                                                 TROS 6002X = organic demulsifier                                         

All numbers are reported in millimeters of separated water and thisparallels the volume. The total separation corresponds to ca. 42 mmreading. Structures employed were made with TMPMAE, except RH-265 andRH-275, and are described in previous Tables of this report.

RH-265 was made with MD44D*11M and polyether and offered very mediocreperformance as diesel defoamer. The low effectiveness of RH-275, madewith TMPMAE formal, is significant and parallels findings for dieseldefoamers. It appears that longer siloxane chains (Example 1 vs Example2 in organosilicone examples) speed up the separation. As personsskilled in this art would appreciate, any general statement should to beavoided due to variety of crudes.

The silicones listed were better than an organic demulsifier at 10 ppmconcentration, but even in the best case (Example 1 in organosiliconeexamples) they were outperformed by the TROS reference employed at 100ppm. The increase of MD100D'24M concentration to 25 ppm did notaccelerate the separation.

Lubricating Oil Performance

Several experiments were carried out with a typical lubricating oil assupplied by one of leading oil companies. The test consisted of passingdispersed air at the rate of 200 cc/min through 200 cc of oil during 5minutes, recording the volume of oil/gas and setting the air flow rateat 100 cc/min during the second part of measurements when the decay offoam is recorded. The virgin oil and that treated with a known industryreference defoamer (available commercially under the trade name "ELF")was tried as control. Figures are collected in Table 9.

                  TABLE 9                                                         ______________________________________                                                         initial volume  volume                                                                              volume                                                  foam    after   after after                                         conc.     volume  1 min   2 min 3 min                                  Antifoam                                                                             ppm       cc      cc      cc    cc                                     ______________________________________                                        none   NA        400     260     220   205                                    control                                                                              200       200                                                          ex. I   50       200                                                          ex. A   50       200                                                          ex. A   20       200                                                          ______________________________________                                    

The total foam abatement was achieved at very low concentration oforganosilicones and the deareation time is substantially reducedcompared to neat dimethylsiloxanes. Where the initial foam volume is 200cc, this indicates the presence of essentially no foam. Deaeration at 20ppm corresponds to the density with an organic reference employed at 200ppm (0.844). Thus, the compounds of the invention provide rates ofdeaeration comparable to organic defoamers, at low treat ratescomparable to silicone oil defoamers.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to those of ordinaryskill in the art that various changes and modifications can be madetherein without departing from the spirit and scope thereof.

The entire contents of all references mentioned above are incorporatedherein by reference.

What I claim is:
 1. An organomodified polysiloxane comprising a polymerof the formula

    MD.sub.x D'.sub.y D".sub.z M,

where M is O₀.5 Si (CH₃)₃, D is OSi (CH₃)₂, D' is OSi (CH₃)R, and R is apolyhydric C₆ -C₂₈ organic group which is completely saturated, D" isOSi (CH₃)R', where R' is a phenol derivative or a long chain aliphaticgroup or polyethers, z is between 0 and 80, x+y+z is between 10-200,x/z≧1, and x/(y+z) is between about 2.0 and about 10.0.
 2. Theorganomodified polysiloxane according to claim 1 wherein R is derivedfrom trimethylolpropane monoallyl ether, ethoxylated pentaerythritolallyl ether formal, propoxylated pentaerythritol allyl ether,tri-isopropanolamine allyl ether, allylpropanediol 1,3, alkoxylatedallyl sorbitol, alkoxylated pentaerythiol, alkoxylated trimethylpropane,or non-alkoxylated trimethylpropane.
 3. The organomodified polysiloxaneaccording to claim 2 wherein R is derived from trimethylolpropanemonoallyl ether.
 4. The organomodified polysiloxane according to claim 1wherein R' is a long chain aliphatic group having between 10 and 20carbon atoms.
 5. The organomodified polysiloxane according to claim 1wherein x+y+z is in the range of 20 to
 160. 6. The organomodifiedpolysiloxane according to claim 1 wherein x/(y+z) is in the range ofabout 3.0 to 6.0.
 7. The organomodified polysiloxane according to claim1 wherein a is in the range of 5 to
 8. 8. The organomodifiedpolysiloxane according to claim 1 wherein x is 100, y is 24 and R isderived from trimethylolpropane monoallyl ether.
 9. The organomodifiedpolysiloxane according to claim 1 wherein R is derived fromtrimethylolpropane monoallyl ether and a is
 7. 10. The organomodifiedpolysiloxane according to claim 1 additionally comprising diesel fuel,wherein the polymer of the formula MD_(x) D'_(y) D"_(z) M is present atabout 1 to about 5 ppm.
 11. The organomodified polysiloxane according toclaim 1 additionally comprising diesel fuel, wherein the polymer of cheformula M'D_(a) M' is present at about 4 ppm.
 12. The organomodifiedpolysiloxane according to claim 1 additionally comprising DAP.
 13. Anorganomodified polysiloxane comprising a polymer of the formula

    MD.sub.x D'.sub.y D".sub.z M,

where M is O₀.5 Si (CH₃)₃, D is OSi (CH₃)₂, D' is OSi (CH₃)R, and R isan alkoxylated polyhydric functionality, D" is OSi (CH₃)R', where R' isa phenol derivative or a long chain aliphatic group or polyethers, z isbetween 0 and 80 x+y+z is between 10-200, x/z≧1, and x/(y+z) is betweenabout 2.0 and about 10.0,or formula

    M'D.sub.a M'

where M' is M is O₀.5 Si (CH₃)₂ R, and R is an alkoxylated polyhydricfunctionality, D is a OSi (CH₃)₂, and a is between 4-10, or mixtures offormula MD_(x) D'_(y) D"_(z) M and formula M'D_(a) M'.
 14. A method ofreducing foaming in diesel fuel comprising adding to diesel fuel asufficient amount of the organomodified polysiloxane of claim
 13. 15.The method according to claim 14 wherein x is 100, y is 24 and R isderived from trimethylolpropane monoallyl ether.
 16. The methodaccording to claim 14 wherein the organomodified polysiloxane comprisingthe polymer of the formula MD_(x) D'_(y) D"_(z) M is present in dieselfuel in an amount of about 1 to about 5 ppm.
 17. The method according toclaim 14 wherein the organomodified polysiloxane comprising the polymerof the formula M'D_(a) M' is present in diesel fuel in an amount ofabout 4 ppm.
 18. The method according to claim 14 which furthercomprises adding at least one solvent.
 19. The method according to claim18, wherein the solvent is selected from the group consisting ofdipropyleneglycol, toluene, 2-ethyl hexanol, isopropanol, aliphaticester alcohols, isophorone, xylene, and mixtures thereof.
 20. Acomposition comprising(a) an organomodified polysiloxane comprising apolymer of the formula

    MD.sub.x D'.sub.y D".sub.z M,

where M is O₀.5 Si (CH₃)₃, D is OSi (CH₃)₂, D' is OSi (CH₃)R, and R is apolyhydric C₆ -C₂₈ organic group which is completely saturated,D" is OSi(CH₃)R', where R' is a phenol derivative or a long chain aliphatic groupor polyethers, z is 0, x+y is between 10-200, and x/y is between about2.0 and about 10.0, or formula

    M'D.sub.a M',

where M' is O₀.5 Si (CH₃)₂ R, and R is as above, D is a OSi (CH₃)₂, anda is between 4-10, or mixtures of formula MD_(x) D'_(y) D"_(z) M andformula M'D_(a) M'; and (b) diesel fuel.
 21. An organomodifiedpolysiloxane comprising a polymer of the formula

    MD.sub.x D'.sub.y D".sub.z M,

where M is O₀.5 Si (CH₃)₃, D is OSi (CH₃)₂, D' is OSi (CH₃)R, where R isan alkoxylated polyhydric functionality, D" is OSi (CH₃)R', where R' isa phenol derivative or a long chain aliphatic group or polyethers, z is0, x+y+z is between 10-200, and and x/(y+z) is between about 2.0 andabout 10.0.